Identification of novel biomarkers of acute phase response in chickens challenged with Escherichia coli lipopolysaccharide endotoxin.

BACKGROUND: The chicken's inflammatory response is an essential part of the bird's response to infection. A single dose of Escherichia coli (E. coli) lipopolysaccharide (LPS) endotoxin can activate the acute phase response (APR) and lead to the production of acute phase proteins (APPs). In this study, the responses of established chicken APPs, Serum amyloid A (SAA) and Alpha-1-acid-glycoprotein (AGP), were compared to two novel APPs, Hemopexin (Hpx) and Extracellular fatty acid binding protein (Ex-FABP), in 15-day old broilers over a time course of 48 h post E.coli LPS challenge. We aimed to investigate and validate their role as biomarkers of an APR. Novel plant extracts, Citrus (CTS) and cucumber (CMB), were used as dietary supplements to investigate their ability to reduce the inflammatory response initiated by the endotoxin. RESULTS: A significant increase of established (SAA, AGP) and novel (Ex-FABP, Hpx) APPs was detected post E.coli LPS challenge. Extracellular fatty acid binding protein (Ex-FABP) showed a similar early response to SAA post LPS challenge by increasing ~ 20-fold at 12 h post challenge (P < 0.001). Hemopexin (Hpx) showed a later response by increasing ∼5-fold at 24 h post challenge (P < 0.001) with a similar trend to AGP. No differences in APP responses were identified between diets (CTS and CMB) using any of the established or novel biomarkers. CONCLUSIONS: Hpx and Ex-FABP were confirmed as potential biomarkers of APR in broilers when using an E. coli LPS model along with SAA and AGP. However, no clear advantage for using either of dietary supplements to modulate the APR was identified at the dosage used.

Measuring the impact of dietary supplementation with citrus or cucumber extract on chicken gut microbiota using 16s rRNA gene sequencing.

This study investigated the effects of dietary supplements, citrus (CTS) and cucumber (CMB), on the jejunum and cecum microbiota of 14- and 28-days old broiler chickens to evaluate their impact on the gut health and assess their role as alternatives to antibiotic growth promoters (ABGPs). 16SrRNA gene sequencing revealed the overall bacterial microbiota composition was significantly affected by the gut site (p?

Pectin oligosaccharides from sugar beet pulp: molecular characterization and potential prebiotic activity.

Pectin oligosaccharides (POS) have been indicated as a new class of potential prebiotic compounds, which can be produced from pectin-rich food byproducts. In the present study, different technological means of POS production were explored to produce tailor-made POS mixtures starting from sugar beet pulp. The overall POS production process consisted of two steps: the extraction of pectin and the hydrolysis of pectin to tailored POS by combined hydrolysis/fractionation approaches. Different extraction as well as hydrolysis and fractionation methodologies were applied. The obtained POS were characterized for their total galacturonic acid content and, at a deeper level, using a HILIC-ESI/MS methodology, for the POS structure and composition. The composition of POS fractions was studied as a function of the technology used to obtain them. Finally, the potential prebiotic properties of the POS mixtures obtained were thoroughly explored by several in vitro experiments aimed at detecting lactic acid bacteria (LAB) stimulation by POS fractions. Several fractions were very efficient in stimulation, in a species-dependent manner. The overall best fractions were in general those rich in arabinans having a low degree of polymerization, obtained from the enzymatic extraction of biomass and subsequent fractionation with low-medium molecular weight cut-off. Quite interestingly, no POS fraction was able to stimulate pathogenic E. coli strains. The data reported here clearly indicate the possibility to obtain diverse fractions with different prebiotic properties starting from the same biomass, and outline clear potential for POS obtained from sugar beet pulp with the appropriate technology to act as prebiotic compounds.

Passive immunization to reduce Campylobacter jejuni colonization and transmission in broiler chickens.

Campylobacter jejuni is the most common cause of bacterium-mediated diarrheal disease in humans worldwide. Poultry products are considered the most important source of C. jejuni infections in humans but to date no effective strategy exists to eradicate this zoonotic pathogen from poultry production. Here, the potential use of passive immunization to reduce Campylobacter colonization in broiler chicks was examined. For this purpose, laying hens were immunized with either a whole-cell lysate or the hydrophobic protein fraction of C. jejuni and their eggs were collected. In vitro tests validated the induction of specific ImmunoglobulinY (IgY) against C. jejuni in the immunized hens' egg yolks, in particular. In seeder experiments, preventive administration of hyperimmune egg yolk significantly (P < 0.01) reduced bacterial counts of seeder animals three days after oral inoculation with approximately 104 cfu C. jejuni, compared with control birds. Moreover, transmission to non-seeder birds was dramatically reduced (hydrophobic protein fraction) or even completely prevented (whole-cell lysate). Purified IgY promoted bacterial binding to chicken intestinal mucus, suggesting enhanced mucosal clearance in vivo. Western blot analysis in combination with mass spectrometry after two-dimensional gel-electrophoresis revealed immunodominant antigens of C. jejuni that are involved in a variety of cell functions, including chemotaxis and adhesion. Some of these (AtpA, EF-Tu, GroEL and CtpA) are highly conserved proteins and could be promising targets for the development of subunit vaccines.

A tolerogenic mucosal immune response leads to persistent Campylobacter jejuni colonization in the chicken gut.

Campylobacter enteritis is the most reported zoonotic disease in many developed countries where it imposes a serious health burden. Campylobacter transmission to humans occurs primarily through the chicken vector. Chicks are regarded as a natural host for Campylobacter species and are colonized with C. jejuni in particular. But despite carrying a very high bacterial load in their gastrointestinal tract, these birds, in contrast to humans, do not develop pathological signs. It seems that in chickens C. jejuni principally harbors in the cecal mucosal crypts, where an inefficient inflammatory response fails to clear the bacterium from the gut. Recent intensive research resulted in an increased insight into the cross talk between C. jejuni and its avian host. This review discusses the chicken intestinal mucosal immune response upon C. jejuni entrance, leading to tolerance and persistent cecal colonization. It might in addition provide a solid base for further research regarding this topic aiming to fully understand the host-bacterium dynamics of C. jejuni in chicks and to develop effective control measures to clear this zoonotic pathogen from poultry lines.

Poultry as a host for the zoonotic pathogen Campylobacter jejuni.

Campylobacteriosis is the most reported foodborne gastroenteritic disease and poses a serious health burden in industrialized countries. Disease in humans is mainly caused by the zoonotic pathogen Campylobacter jejuni. Due to its wide-spread occurrence in the environment, the epidemiology of Campylobacter remains poorly understood. It is generally accepted, however, that chickens are a natural host for Campylobacter jejuni, and for Campylobacter spp. in general, and that colonized broiler chicks are the primary vector for transmitting this pathogen to humans. Several potential sources and vectors for transmitting C. jejuni to broiler flocks have been identified. Initially, one or a few broilers can become colonized at an age of >2 weeks until the end of rearing, after which the infection will rapidly spread throughout the entire flock. Such a flock is generally colonized until slaughter and infected birds carry a very high C. jejuni load in their gastrointestinal tract, especially the ceca. This eventually results in contaminated carcasses during processing, which can transmit this pathogen to humans. Recent genetic typing studies showed that chicken isolates can frequently be linked to human clinical cases of Campylobacter enteritis. However, despite the increasing evidence that the chicken reservoir is the number one risk factor for disease in humans, no effective strategy exists to reduce Campylobachter prevalence in poultry flocks, which can in part be explained by the incomplete understanding of the epidemiology of C. jejuni in broiler flocks. As a result, the number of human campylobacteriosis cases associated with the chicken vector remains strikingly high.

The cinnamon-oil ingredient trans-cinnamaldehyde fails to target Campylobacter jejuni strain KC 40 in the broiler chicken cecum despite marked in vitro activity.

Campylobacter jejuni is the most common bacterial cause of diarrheal disease in humans worldwide, with poultry products being a major source. Therefore, strategies to decrease Campylobacter colonization during primary production might aid in reducing the number of human campylobacteriosis cases. Several plant-derived compounds have been reported to possess anti-Campylobacter properties in vitro, so they could be promising candidates to reduce Campylobacter colonization in broiler chickens. To test this hypothesis, selected plant-derived antimicrobials (caffeic, gallic, protocatechuic, and vanillic acids, epigallocatechin gallate, trans-cinnamaldehyde, and thymol) were screened for anti-Campylobacter activity by determining MICs and setting up time-kill curves for C. jejuni strain KC 40. These experiments revealed marked antibacterial activity, especially for the cinnamon oil ingredient trans-cinnamaldehyde (CIN). This compound was tested in a broiler chick seeder model; it was added to the feed in coated form at an effective concentration of 0.3 % from day-of-hatch for the entire 22-day duration of the experiment. At 14 days of age, one-third of the birds were inoculated with C. jejuni strain KC 40 and served as seeders. CIN was not able to reduce cecal Campylobacter colonization in this model, which was confirmed in a cecal loop experiment. Despite CIN concentrations much higher than the MIC, C. jejuni numbers were not reduced compared with those in nontreated ceca at 2 and 24 h after injection. In conclusion, this study shows a marked discrepancy between in vitro and in vivo activity of CIN against C. jejuni strain KC 40.

Colonization factors of Campylobacter jejuni in the chicken gut.

Campylobacter contaminated broiler chicken meat is an important source of foodborne gastroenteritis and poses a serious health burden in industrialized countries. Broiler chickens are commonly regarded as a natural host for this zoonotic pathogen and infected birds carry a very high C. jejuni load in their gastrointestinal tract, especially the ceca. This eventually results in contaminated carcasses during processing. Current intervention methods fail to reduce the colonization of broiler chicks by C. jejuni due to an incomplete understanding on the interaction between C. jejuni and its avian host. Clearly, C. jejuni developed several survival and colonization mechanisms which are responsible for its highly adapted nature to the chicken host. But how these mechanisms interact with one another, leading to persistent, high-level cecal colonization remains largely obscure. A plethora of mutagenesis studies in the past few years resulted in the identification of several of the genes and proteins of C. jejuni involved in different aspects of the cellular response of this bacterium in the chicken gut. In this review, a thorough, up-to-date overview will be given of the survival mechanisms and colonization factors of C. jejuni identified to date. These factors may contribute to our understanding on how C. jejuni survival and colonization in chicks is mediated, as well as provide potential targets for effective subunit vaccine development.

Campylobacter control in poultry by current intervention measures ineffective: urgent need for intensified fundamental research.

Campylobacter-contaminated poultry meat is an important source of foodborne gastroenteritis and poses a serious health burden in industrialized countries. Broiler chickens are commonly regarded as a natural host for this pathogen and infected birds carry a very high Campylobacter load in their gastrointestinal tract, especially the ceca. This results in contaminated carcasses during processing. While hygienic measures at the farm and control measures during carcass processing can have some effect on the reduction of Campylobacter numbers on the retail product, intervention at the farm level by reducing colonization of the ceca should be taken into account in the overall control policy. This review gives an up-to-date overview of suggested on-farm control measures to reduce the prevalence and colonization of Campylobacter in poultry.